1. Field of the Invention
The present invention is directed to a cost-effective device for affixing register marks to superposed sheets to enable the separation and precise reassembly of the sheets.
2. The Prior Art
In various fields of graphic arts artistic and like representations are effected on two or more superposed sheets disposed in fixed position relative to each other, portions of the overall representation being executed on one sheet and other portions on a different sheet.
By way of example, in the making of multi-color engravings, portions of the engraving to appear in one color are executed on a first sheet, with successive transparent sheets thereafter being superposed and while thus positioned having other portions of the design executed thereon. The various sheets are thereafter separated for the fabrication of engraving plates embodying different colors.
In order to assure precise assemblage of the images defined by the respective plates so as to avoid blurring, fringing or the like, it is conventional practice for the artist to position so-called index marks in the form of crosses or the like on the respective sheets to be replicated. The positioning of such marks on an individual basis represents a time-consuming operation since any inaccuracy is reflected in the finished artwork.
In accordance with the method of applying such marks, a dry transfer sheet carrying the mark is positioned and activated by burnishing to cause the mark to be removed from a carrier sheet to the artwork. Thereafter the process is repeated for a second and additional sheets, in each instance precise positioning of subsequent index marks being required. Since multiple index marks must be used with each sheet, the time consuming nature of this operation will be readily recognized.
U.S. Pat. Nos. 3909,329 and 4015,034, issued to the inventor hereof, represent efforts to provide a device which facilitates the locating or juxtaposition of sequential sheets in an expedited manner.
Briefly, U.S. Pat. No. 3909,329 disclosing a marking device wherein opposite faces of a carrier bear index marks in precise registry with each other, the device being used by interposing the same between superposed sheets and burnishing the sheets whereby dry transfer index marks are released to the facing surfaces of the sheets.
While the device is effective for its intended purpose, commercial manufacture of the product has proven difficult due to the difficulties inhering in printing in precise registry on opposed surfaces of a sheet.
U.S. Pat. No. 4015,034 discloses a marking device wherein a dry transfer film on a carrier is disposed between two juxtaposed sheets and, following burnishing, leaves an image on one such sheet and a silhouette thereof on the other sheet.